Seed entrainment unit

ABSTRACT

The invention is directed broadly to an entrainment unit for distributing seed, comprising: a seed chamber for seed in bulk; a mixing chamber for mixing seed and air, the mixing chamber having an outlet for discharging entrained seeds; and an air supply unit for: (a) supplying a first air flow to the seed chamber and entraining and transporting seed to the mixing chamber, and (b) supplying a second air flow to the mixing chamber for forming a combined air flow that entrains the seed and transports the seed through the discharge outlet.

TECHNICAL FIELD

The invention relates to the field of agricultural equipment.Specifically, the invention relates to an entrainment unit fordistributing seed and grain from a bulk storage source and a method ofdistributing seed using the entrainment unit.

BACKGROUND

The control and precision with which seed is distributed via a seeder isan important issue.

Typically, a seeder operates as follows to deliver seed to a field: thebulk seed is delivered to a hopper; the hopper divides the seed intoindividual portions; the individual portions are entrained in air andsent through a metering device; and the metering device transfersindividual seeds to a planting wheel to be dispersed to the soil.Interference with any one of the above steps can jeopardise theindividual seed distribution to the planting wheel and further disrupt asteady, uninterrupted flow of seed to a field.

Different seed has different sizes, for example, crops like canola andwheat may have seed of 2-3 mm, while corn and fava beans can be close to7-8 mm in size. As such, the equipment used for dispersing the seed mustcater for a range of seed sizes and weights, for efficient use. This cancause problems where a farmer needs to shift quickly between plantingone crop type to another. If the distribution system is configured forsmall seeds there may not be sufficient air flow to entrain large seeds.Conversely, if the system is configured for larger seeds the air flowcan be too high for small seed and block the flow by entraining too manysmall seeds in the air flow.

The present invention was conceived with these shortcomings in mind.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, a limitednumber of the exemplary methods and materials are described herein.

SUMMARY OF THE INVENTION

In broad terms, the invention provides an entrainment unit fordistributing seed, comprising: a seed chamber for seed in bulk; a mixingchamber for mixing seed and air, the mixing chamber having an outlet fordischarging entrained seeds; and an air supply unit for: (a) supplying afirst air flow to the seed chamber and entraining and transporting seedto the mixing chamber, and (b) supplying a second air flow to the mixingchamber for forming a combined air flow that entrains the seed andtransports the seed through the discharge outlet.

In one aspect of the invention, there is provided an entrainment unitfor distributing seed, comprising: a seed chamber for seed in bulk; amixing chamber for mixing seed and air, the mixing chamber having anoutlet for discharging entrained seeds; and an air supply unit having asingle air outlet divided into a first passageway and a secondpassageway for: (a) supplying a first air flow via the first passagewayto to the seed chamber so that the first air flow travels across theseed chamber and entraining and transporting seed to the mixing chamber,and (b) supplying a second air flow via the second passageway extendingaround the seed chamber and directly into the mixing chamber for forminga combined air flow that entrains the seed and transports the seedthrough the discharge outlet.

The entrainment unit may be adapted to provide a laminar air flowupstream of the mixing chamber.

The entrainment unit may be adapted to provide a turbulent air flowwithin the mixing chamber.

The air supply unit may comprise an air chamber for receiving air froman air source, such as a motor driven fan or a compressed air source,and for supplying air as the first air flow to the seed chamber and airas the second air flow directly to the mixing chamber without passingthough the seed chamber.

The air chamber may comprise an inlet for air flow into the air chamberand two outlets for the first air flow and the second airflow to exitthe air chamber.

The air chamber may comprise an inlet for air flow into the air chamberand the air outlet may provide two discrete outlets to exit air from theair chamber, a first outlet for the first air flow to exit the firstpassageway and a second outlet for the second airflow to exit the secondpassageway into the mixing chamber.

A first outlet of the air chamber may comprise a first passageway influid communication with the seed chamber and a second outlet of the airchamber comprises a second passageway in fluid communication with themixing chamber. The first and second passageways may be parallel to eachother.

The entrainment unit may include a common wall that separates the firstand second passageways. The common wall may extend from the air chamberto the mixing chamber. The common wall may comprise three portions,namely an inclined portion situated at least partially in the airchamber; a seed chamber portion that extends between the air chamber andthe mixing chamber; and an upwardly curved portion that extends into themixing chamber.

The inclined portion of the common wall may provide a leading edge toseparate airflow exiting the air chamber into the first and the secondair flows.

The upwardly curved portion of the common wall may be configured tocause the first and second passageways to supply the first and secondair flows upwardly into the mixing chamber as parallel streams of airthat promote turbulence in the mixing chamber.

The seed chamber portion of the common wall may define a lower wall ofthe seed chamber.

An internal baffle may separate the mixing chamber and the seed chamber.The baffle may include a curved surface for reducing turbulence in thecombined air flow near the discharge outlet. The air chamber may be ahigh-pressure chamber.

The seed chamber may have a volume similar to a volume of the airchamber. The seed chamber may be a low-pressure chamber. The seedchamber may have a larger volume than a volume of the mixing chamber.The seed chamber may have a substantially V-shaped cross-section. Theseed chamber may provide an open mouth for receiving seed in bulk.

The seed chamber may include a pair of inclined side walls for funnelingseed under gravity feed towards the mixing chamber. Seed may movethrough the seed chamber under the force of gravity.

The entrainment unit may be configured such that each of the first andsecond air flows are of a similar volume. Alternatively, each of thefirst and second air flows may be of a dissimilar volume.

The discharge outlet may provide a conduit extending from the mixingchamber. The conduit may extend at an angle of less than 90 degrees fromthe flow direction of the combined air flow and entrained seed.

The entrainment unit may further comprise a sealable opening tofacilitate access to an interior of the unit. The sealable opening maybe located on a lower portion of the entrainment unit, when the unit isinstalled for use, such that seed evacuates the entrainment unit via theopening under the force of gravity. The sealable opening may be sealedby a closer configured to be pivotally connected to the entrainmentunit. A portion of the common wall may be mounted to the closer to beremovably located within the entrainment unit.

The entrainment unit may further comprise at least one mounting flangefor engaging with a seed hopper.

The entrainment unit may comprise two parallel side walls forcooperative engagement with a subsequent entrainment unit.

The entrainment unit may comprise: a pair of end plates, an access paneland an internal wall form.

The internal wall form may comprise the discharge outlet. Each of theinternal walls and the common wall may be configured as a singleintegrated moulding. The wall form may comprise at least one of aplastic, fibreglass, moulded composite, and fibre reinforced plastic.

In another embodiment, there is provided a method of distributing seed,comprising the steps of: supplying seed in bulk to a seed chamber;entraining seed in a first air flow in the seed chamber; transportingthe seed from the seed chamber into a mixing chamber; supplying a secondair flow directly to the mixing chamber so that the first and second airflows mix seed entrained in the first air flow in the mixing chamber andtransporting the seed through a discharge outlet of the mixing chamber.

The method may further comprise a step of supplying the first air flowand the second air flow as parallel air flows into the mixing chamber sothat the second air flow facilitates drawing the first air flow withentrained seed into the mixing chamber and minimises the possibility ofblockages of the entrained seed from the seed chamber.

The method may further comprise a step of supplying the first air flowto the seed chamber as a laminar flow.

The method may further comprise a step of supplying the second air flowto the mixing as a laminar flow.

The method may further comprise a step of supplying the first air flowand entrained seed to the mixing chamber and creating a turbulent flowin the mixing chamber.

The method may further comprise a step of creating the turbulent airflow upon entry to the mixing chamber.

The method may further comprise a step of attaching a hose to thedischarge outlet to direct the entrained seed and air mixture to a seedmetering unit. The method may further comprise a step of attaching ahopper to an inlet of the entrainment unit to supply seed thereto. Themethod may further comprise a step of sensing the capacity of seedwithin the entrainment unit to control the flow of seed thereto from thehopper.

In a further embodiment, there is provided a method of constructing amulti-outlet entrainment unit, the entrainment unit comprising aplurality of wall forms, each wall form having a seed chamber, a mixingchamber and a discharge outlet, the method comprising the steps of:orienting a plurality of wall forms, in side-by-side relationship, toform a collective seed chamber therebetween; sealing the sides of thecollective seed chamber; connecting an air supply unit to the collectiveseed chamber to provide: (i) a first air flow to drive seed from thecollective seed chamber via the first air flow toward each of theplurality of mixing chambers, and (ii) a second air flow communicateddirectly into each of the plurality of mixing chambers, such that thefirst and second air flows mix seed entrained in the first air flow ineach of the mixing chambers to transport the seed through a dischargeoutlet of each mixing chamber.

Each wall form may further comprise a common wall configured to separatethe first air flow from the second air flow.

The method may further comprise a step of converting the first laminarair flow and entrained seed therein into a turbulent air flow uponentering each of the mixing chambers.

The method may further comprise the step of attaching a hopper to aninlet of the collective seed chamber to supply seed thereto in bulk.

Various features, aspects, and advantages of the invention will becomemore apparent from the following description of embodiments of theinvention, along with the accompanying drawings in which like numeralsrepresent like components.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example, and notby way of limitation, with reference to the accompanying drawings, ofwhich:

FIG. 1 is an exploded perspective view of a wall form, a sealable doorand a closing plate, that together form an entrainment unit according toan embodiment of the invention;

FIG. 2 is a perspective view of the wall form of the entrainment unit ofFIG. 1, formed in a single moulded unit;

FIG. 3 is a schematic view of an entrainment unit illustrating the flowof seed and air through the unit;

FIG. 4 is a perspective view of the wall form of FIG. 2, illustratingthe door in a closed configuration in a lower portion thereof;

FIG. 5 is a sectional view through the centreline of a discharge outletof the wall form of FIG. 4;

FIG. 6 is a perspective view of a plurality of wall forms positionedside-by-side and sealed with a closing plate, to form a collective seedchamber within the plurality of discharge outlets;

FIG. 7 is a perspective view of an entrainment unit comprising aplurality of wall forms mounted under a seed hopper;

FIG. 8 is a perspective view of a planter, having an entrainment unitcomprising a plurality of wall forms mounted under a seed hopper;

FIG. 9 is a front view of a seed distribution system, illustrating aplurality of conduits, each conduit extending from a discharge outlet ofthe entrainment unit to a separate seed metering unit;

FIG. 10A is a perspective view of the entrainment unit, illustrating aplurality of stiffening webs on an exterior side of the door;

FIG. 10B is a perspective view of the entrainment unit, illustrating alatch for holding the door closed;

FIG. 11A is a perspective view of a closed formwork side of theentrainment unit, illustrating a plurality of recesses for receivingwalls of an adjacent wall form when stacked together side-by-side; and

FIG. 11B is a perspective view of an open formwork side of theentrainment unit, illustrating the plurality of walls to be received inthe recesses of an adjacent wall form when stacked together side-by-side(as shown in FIG. 11A).

Embodiments will now be described more fully hereinafter with referenceto the accompanying drawings, in which various embodiments, although notthe only possible embodiments, of the invention are shown. The inventionmay be embodied in many different forms and should not be construed asbeing limited to the embodiments described below.

DETAILED DESCRIPTION OF EMBODIMENTS

Whist the entrainment unit is described herein in relation to entrainingseeds or grain within an air flow, it is contemplated that theentrainment unit is applicable to for entraining and dispersing avariety of items delivered in bulk that may need to be separated anddistributed in a controlled manner, for example pellets, food stuffs andthe like.

With reference to FIG. 1, there is illustrated an entrainment unit 1 fordistributing seed, comprising:

-   -   a seed chamber 10 for seed in bulk;    -   a mixing chamber 20 for mixing seed and air, the mixing chamber        20 having a discharge outlet 25 for discharging entrained seeds;        and    -   an air supply unit 31 for: (a) supplying a first air flow 32 to        the seed chamber 10 and entraining and transporting seed to the        mixing chamber 20, and (b) supplying a second air flow 34 to the        mixing chamber 20 for forming a combined air flow 36 that        entrains the seed and transports the seed through the discharge        outlet 25.

The entrainment unit 1 comprises an internal wall form 5 and a pair ofend plates 15 (only one illustrated in FIG. 1) which partially seal thewall form 5. The wall form 5 and the end plates 15 define the seedchamber 10, mixing chamber 20, and air supply unit 31.

The entrainment unit 1 further comprises a door 40 for accessing atleast one of the seed chamber 10 and the mixing chamber 20.

A plurality of mounting holes 16 are formed in the end plates 15 whichcorrespond with a plurality of mounting apertures 6 in the wall form.The mounting apertures 6 of the wall form 5 can be threaded to securethe end plate 15 thereto. Alternatively, the mounting apertures 16 canextend entirely through the wall form 5 and through each of the pair ofend plates 15 to be secured externally of the entrainment unit 1. Theend plates 15 can be connected, for example, by using a nut, bolt,circlip, spring clip or the like that can be easily engaged or removed,when access to the interior chambers 10, 20, 30 is required. The endplate 15 is tightened against an abutting edge 56 of the wall form 5.The abutting edge 56 can be flat, or tapered, to assist in reducing airloss from within the entrainment unit. In some embodiments, the abuttingedge 56 can be profiled to seat a seal (not illustrated).

In some embodiments, the abutting edge 56 protrudes from the wall form5, to be received in a complementary recess 57 on the closed side wall19 of the wall form 5 (see FIG. 11B). In some embodiments the closedside wall 19 provides a plurality of recesses 57, 57 a, 57 bthereacross, each positioned and dimensioned to receive a complementaryedge of the front face of the wall form surrounded by the abutting edge56 (see FIG. 11A). For example, the recess 57 a is shaped anddimensioned to receive an edge 29 a of the curved portion 29 of the wall27 of the seed chamber 10. Additionally, recess 57 b is shaped anddimensioned to receive an edge 26 a of the first inclined wall 26 of themixing chamber 20 which travels diagonally across the internal cavity 11of the wall form 5. These edges and complementary recesses provide for asnug fit between adjacent wall forms 5 (and entrainment units 1, whenassembled in side-by-side relationship. The edges and recess assist inaligning adjacent entrainment units 1 and reduce the need for seals orgaskets between adjacent units. The edge and recess receiving the edgeact like a labyrinth-type seal to prevent air from the air chamber of afirst unit 1 escaping into an adjacent unit 1′.

At least one of the end plates 15 provides an air inlet manifold 84 forconnection with a hose 85 providing an air source to the unit 1. The airsource can be a pressurised air source depending on the required flow ofthe unit 1. It is contemplated that a working pressure range for the airsupply 31 could vary from 0 psi-2000 psi. The wall form 5 can comprisean air intake aperture 21 for receiving an air supply into the unit 1.While it is contemplated that a single air source will run theentrainment unit 1, an air supply can be introduced through each of theend plates 15 to either increase the air flow though the unit 1, or moreevenly disperse the air flow through the unit 1.

The end plate 15 further provides a mounting flange 22 for securing theend plate 15 to a hopper 80. This leaves the entrainment unit 1 with noexternal moving parts during use. This may increase the working life ofthe unit 1 and further may reduce the opportunity for injury to personsworking the unit 1 and attached planter.

In some embodiments of the entrainment unit 1, a plurality of wall forms5 are abutted to one another side-by-side, to form a multi-outlet 25entrainment unit 1 (see FIG. 6). In this configuration a single pair ofend plates 15 is used to seal each of the outermost wall forms 5, tocreate a single seed chamber 10 with multiple outlets 25. The pair ofend plates 15 can provide an air inlet manifold 84 at each end of thearray of wall forms 5.

Turning to FIG. 2, the wall form 5 is illustrated in isolation. The wallform 5 can be formed from a plurality of individual components, or asillustrated in FIG. 2, can be formed in a one-piece moulding or casting.

Wall Form Exterior

The wall form 5 will be described herein in reference to a workingorientation, illustrated in FIG. 2, where seed is introduced into theunit 1 from an open top surface 3. The seed falls from a hopper 80 (notillustrated in FIG. 2) into the seed chamber 10 wherein the seed movesthrough the unit 1 under gravitational force in combination with airflow through the unit 1.

The open top surface 3 of the unit 1 further provides a pair of mountingflanges 4 disposed on opposing sides of the top 3. The mounting flanges4 are configured to be directly mounted to the seed hopper 80 forreceiving seed in bulk. In FIG. 2 the flanges 4 are provided with holes7 for receiving a bolt, screw, nail, pin, clip or the like forreleasably securing the entrainment unit 1 to the hopper 80.

Typically, the hopper 80 can receive as much as 60 kg of seed in oneload, which is then slowly distributed to the entrainment unit 1. Thefeeding of the entrainment unit 1 can be monitored and even controlledby use of a Venturi valve that monitors the height of seed within theseed chamber 10 at any given time. When seed in the seed chamber 10 isat a sufficient height to block the venture valve, the seed flow fromthe hopper 80 is stopped. As the seed chamber 10 empties and the heightof seed in the seed chamber 10 drops below a location of the Venturivalve, the flow of seed from the hopper 80 is restarted.

The wall form 5 is configured so that it can be injection moulded from asuitable plastics material, for example ABS; PPE; PE or PET or relatedglass reinforced plastic material. UV stabilisers and other additivescan be introduced into the material of the wall form 5 to improvemechanical characteristics of the wall form 5, such as strength,durability, UV resistance and working life, as may be required. Theinvention is not limited to this method of manufacturing the wall form 5or the materials selection.

Discharge Outlet

A front face 8 of the wall form 5 provides a discharge outlet of theunit 1 in the form of a snorkel 25. The snorkel 25 projects outwardlyfrom the front face 8 of the wall form 5. The snorkel 25 projectsupwardly towards the open top surface 3 of the unit 1.

The snorkel 25 extends upwardly away from the vertical front face 8 ofthe wall form 5, at an inclination angle α. The angle α is greater than90 degrees, from the vertical, to provide a steady egress to theentrained seed and air mixture. If the angle α is less than 90 degreesthe entrained seed and air mixture must turn through the 90 degree anglewhile being discharged from the snorkel 25, the change in velocity cannegatively affect the flow of the entrained seed: by losing speed;causing the seed to impact the sides of the snorkel 25 and mixingchamber wall; and potentially damming the snorkel 25.

In FIG. 5, the angle α is about 135 degrees from the vertical front face8 of the wall form 5. This snorkel angle works in concert with a curvedwall 29 that is shared between the seed chamber 10 and the mixingchamber 20, to guide the flow of entrained seed and air from the mixingchamber 20 to the snorkel 25 smoothly.

The snorkel 25 is supported by a pair of webs 9 integrally formed withthe wall form 5. The webs 9 strengthen the snorkel 25 and providestability thereto. In use, the snorkel 25 will be attached to adischarge hose 86 (illustrated in FIGS. 8 and 9).

A distal end 24 of the snorkel 25 is configured to receive and engagewith the discharge hose 86. The distal end 24 of the snorkel 25 providesa plurality of projections 23 for hose 86 engagement. The projections 23can be integrally formed in the wall form 5. Alternatively, theprojections 23 can be formed as part of a mounting collar (notillustrated) to be attached to the wall form 5 in a separatemanufacturing operation.

A base 12 of the wall form 5 also provides an opening, wherein the baseof the unit is disposed on an opposing side of the unit 1 to the topsurface 3. The base 12 provides an opening 13 through which seed andother trapped seed can be released from within the entrainment unit 1.The opening 13 is formed in a base 12 of the unit 1 such thatgravitational force will cause trapped seed in the unit 1 to fall out ofthe opening 13. The opening 13 is sealed during operation of the unit 1by the door 40.

The base 12 of the wall form 5 provides at least one bracket 14 (threeillustrated in FIG. 2) to which the door 40 is pivotally mounted. Theprotrusions 14 each provide a central aperture 17 for receiving a pin(not illustrated) wherein the pin mounts the door 40 to the protrusions14 allowing the door 40 to pivotally rotate about an axis that extendsthrough each of the central apertures 17.

A rear face 18 of the wall form 5 is partially arcuate, externallycurving around the air chamber 30 within.

A side wall 19 of the wall form 5, adjacent the rear face 18, providesthe air intake aperture 21. The air intake aperture 21 is rounded andprovides an unobstructed air intake to the air chamber 30

The side wall 19 does not extend the width and breadth of the wall form5. As such, the unit 1 relies on the pair of end plates 15 to seal thesides of the wall form 5. The side wall 19 fully seals one side of themixing chamber 20. This prevents seed in the mixing chamber 20 fromintermingling with seed in an adjacent mixing chamber 20′ of an adjacentwall form 5′ when a plurality of wall forms 5 are combined to form theunit

The side wall 19 partially seals the seed chamber 10. Where the unit 1is formed from a plurality of wall forms 5 the seed chambers 10 of eachwall form 5 combine to receive seed from the hopper 80. A function ofthe side wall 19 is to hold the wall form 5 in one-piece such that thewall form 5 can be handled prior to be combined with at least one endplate 15.

Strengthening the rear face 18 of the wall form 5, and extending betweenthe arcuate rear face 18 and the mounting flange 4 is an additional web9 a.

An internal cavity 11 of the unit 1 is partitioned to form the threechambers: the seed chamber 10, the air chamber 30; and the mixingchamber 20, each of which will now be described in further detail inreference to the embodiments illustrated in FIGS. 1 to 4.

Seed Chamber

The seed chamber 10 is configured in a V-shape, extending from the opentop surface 3 of the wall form 5, and narrowing towards the base 12 ofthe wall form 5. The seed chamber 10 provides a chute for the seed totravel through, from the hopper 80 to the mixing chamber 20.

A first inclined wall 26 of the mixing chamber 20 travels diagonallyacross the internal cavity 11 of the wall form 5, from the mountingflange 4 towards the base 12 of the wall form 5. The inclined wall 26separates the seed chamber 10 from the air chamber 30.

An opposing wall 27 of the seed chamber 10 provides a straight portion28 and a curved portion 29. The curved portion 29 of the wall 27 of theseed chamber 10 separates the seed chamber 10 from the mixing chamber20.

At the lowest point of the seed chamber 10 there is a baffle 50. Thebaffle 50 separates the first air flow 32 from the second airflow 34upon their exit from the air chamber 30. Adjacent the baffle 50 the seedwithin the seed chamber 10 is brought into contact with the first airflow 32 to entrain the seed therein and transport the seed towards themixing chamber 20.

As the seed in seed chamber 10 comes into contact with the first airflow 32, the seed is transported towards the mixing chamber 20. Thisaction then allows further seed within the seed chamber 10 to falltowards the baffle 50 under gravitational force to continue to pull theseed through the entrainment unit 1.

Air Supply Unit

The air supply unit 31 comprises an air supply (not illustrated), pumpedinto the air chamber 30 via an air hose 85 and at least a first airpassage 33 and a second air passage 35 within the cavity 11, separatingthe incoming air into the first air flow 32 and the second air flow 34.

Where a plurality of wall forms 5 are arranged to form the unit 1, asingle air source can be used, driving air into the unit 1 from the airhose 85 into at least one of the end plates 15. If additional air flowis required, an air intake manifold 84 can be provided in each of thetwo end plates 15 to introduce air into the entrainment unit 1 from bothends thereof.

FIGS. 3 and 5 are schematic side views of the wall form 5, clearlyidentifying the first passage 33 and second passage 35 exiting the airchamber 30, through which the first flow 32 and second flow 34 of airare respectively discharged from the air chamber 30 to interact with theincoming seed from the seed chamber 10.

An internal wall 55 extends into the air chamber 30. The wall 55 extendsfrom the base 12 of the wall form 5 and travels parallel to the inclinedwall 27 of the seed chamber 20 creating an air outlet 37 from the airchamber 30. The air outlet 37 is divided into the two passages 33, 35 bythe internal baffle 50.

The two passages 33, 35 run parallel to one another and are inclined tothe base 12 of the wall form 5, extending inwardly and upwardly into theair chamber 30. This upwards inclined angle of the two passages 33, 35assists in preventing, or at least reducing, seed from being blow out ofthe seed chamber 10 and into the air chamber 30. Although this isunlikely when the unit 1 is in use and there is a positive air flowthrough the unit 1, there are disruptions to the air supply to the unit1 each time the unit 1 is started-up and stopped. It is preferable thatseed is not drawn back into the air chamber 30 from the seed chamber 20at these times.

The baffle 50 extends along the air outlet 37 parallel to the adjacentwalls 27, 55. In the embodiment of FIGS. 1-4 the two passages 33, 35 areof a similar volume. However, it is contemplated that the passages 33,35 can be of dissimilar volumes in some embodiments of the invention, tothereby vary the volume of air flow in the first air flow 32 compared tothe volume of air flow in the second air flow 34.

Air exits the air chamber 30 via an air chamber outlet 37. As the airleaves the air chamber 30 via the outlet 37, the baffle 50 continuouslyseparates the first air flow 32 from the second air flow 34.

The baffle 50 extends across a lower portion of the seed chamber 20parallel to the base 12 of the wall form 5 before continuing towards anentrance 38 to the mixing chamber 20. This form to the baffle 50 guidesthe first air flow 32 horizontally across the base of the seed chamber10, constantly passing the first air flow across the head of theimpinging seed, thereby urging the seed towards the mixing chamber 20.The baffle 50 continues to extend into the mixing chamber 20.

The smooth curves of the baffle 50 facilitate a smooth, planar air flowalong each of the first and second air flows 32, 34. This provides anefficient flow of air through the unit 1.

As the baffle 50 enters the mixing chamber 20, an end lip 52 of thebaffle 50 curves upwardly into the mixing chamber 20 to direct air flowinto the mixing chamber 20.

Where the first air flow 32 contacts the lip 52 of the baffle 50, theair flow 32 is converted from a laminar flow to a turbulent flow uponentering the mixing chamber 20. This is partly due to the air flow 32being forced into he upturned lip 52, against the horizontal air flow,which causes a sharp or sudden change in direction to the first passageand this the air flow 32 within. The change in direction caused by thelip 52 is also coupled with a termination of the baffle 50. The air flowtraveling along the baffle 50 sticks to the surface of the baffle 50 andbecomes disrupted when the baffle 50 terminates. This disruption of thefirst flow 32 is further excited by the introduction of the second airflow 34 (which is free from seed) and enters the mixing chamber directlyas the baffle 50 terminates. The turbulence created in the first airflow 32 swirls the entrained seed within the air flow 32 and therebyreduces the seed from becoming clogged at an entrance 38 to the mixingchamber 20. Seed entering the mixing chamber 20 entrained within thefirst air flow 32 is prevented from exiting the mixing chamber 20 byboth the incoming seed and air mixture within the first air flow 32 andthe second air flow 34 entering the mixing chamber 20 from below thebaffle 50.

The second air flow 34 exits the air chamber 30 via the air chamberoutlet 38 and is channeled along the second flow passage 35, the secondpassage 35 being separated from the seed chamber 10. The second air flow34 does not contact entrained seed within the first air flow 32 untilthe second air flow 34 enters the mixing chamber 20.

The second air flow 34 is directed along the second flow passage 35which extends along the baffle 50 on an opposing side to that of theseed chamber 10.

The smooth curves of the baffle 50 facilitate a smooth, planar air flowalong each of the air flows 32, 34. The second air flow 34 is guided,smoothly along the underside of the baffle 50, into the mixing chamber20 along the upturned lip 52 of the baffle 50.

As the second air flow 34 enters the mixing chamber 20 the second airflow 34 is instantly brought into contact with the turbulent first airflow 32 and entrained seed therein. The first and second air flows 32,34 then become combined to form a combined air flow 36 with the seedentrained therein. The combined air flow 36 and entrained seed are thendirected through the mixing chamber 20 towards the snorkel 25.

The combination of dual air flows provided within the unit 1 can beapplied across a range of sizes of seeds (such as fava beans or canola),without the need to constantly adjust internal baffles of the unit 1 oradjust the air supply to the unit 1. The thorough mixing of the seed andair that is induced by the dual air flows may also prevent blockageswithin the passageways of the unit 1, thereby reducing down-time of theplanter.

Mixing Chamber

The mixing chamber 20 is formed by the front wall 8 of the wall form 5,a portion of the base 12 of the wall form 5, the two incoming airpassages 33, 35 on opposing sides of the baffle 50, and the curved lowerwall 29 (shared with the seed chamber 10).

At a lowermost portion of the curved wall 29 there is formed a lip 39that extends inwardly into the mixing chamber 20. The lip 39 guides seedfrom the seed chamber 20 towards the entrance to the mixing chamber 38.

The lip 39 extends into the mixing chamber 20 at an angle similar tothat of the inclined first wall 27 of the seed chamber 10. The lip 39extends into the mixing chamber 20 by only a few centimetres, such thatan imaginary extension of the lip 39 (illustrated as dotted line 37 a inFIG. 5) passes just in front of the upturned lip 52 of baffle 50.

The lip 39 channels the combined air flow 36 within the mixing chamber20 to reduce the combined air flow 36 being directed back towards theseed chamber 20 and potentially disrupting the steady flow of the seedentrained within the first air flow 32, upon entry into the mixingchamber 20.

An uppermost portion of the curved wall 29, provides a gradual, planarcurved surface to guide the seed entrained within the combined air flow35 towards the snorkel 25 to minimise the opportunity for seed to damthe snorkel 25 on exiting the unit 1.

Referring now to FIGS. 1 and 3-5, the baffle 50 is illustrated to bepartially formed with the door 40. Best illustrated in the perspectiveview of FIG. 1, the door 40 comprises a pair of cylindrical members 41for encasing a pin between the brackets 14 to form a door hinge 42.Alternative means for forming a hinge 42 to pivotally connect the door 4to the wall form 5 are also contemplated. For example, either of thebrackets 14 or the cylindrical members 41 can be formed with aninterconnected pin for directly mounting to each other. Alternatively,the cylindrical members 41 can be made from a resilient material tosnap-fit into the brackets 14 of the wall form 5. In alternativeembodiments, the door 40 can comprise a resilient material or aresilient seal to be compressed into the opening 13 and held in place bycompression of the resilient material alone.

The door 40 further comprises a gripping portion, illustrated in FIG. 1as a handle 43. The handle 43 facilitates access to open and close thedoor 40 while the unit 1 is attached under a hopper 80. The handle 43can comprise a resilient material to snap-fit into engagement with a rim45 of the wall form 5. In an alternative embodiment the handle 43 can befitted with a key or other twist activated locking member. However, anyprotrusion or obstruction into the flow passages 33, 35 may restrict theair flows 32, 34 therein.

As the door 40 opens in the base 12 of the wall form 5, any seed at thebottom of the seed chamber 10, in the first passage 33 and the secondpassage 35 can be evacuated from the unit 1. This is facilitated by anupper door portion 44 which provides a removable segment to the baffle50.

The upper door portion 44 comprises a hollow rectangular prism. A topsurface 47 of the upper door portion 44 is planar and, when the door 40is closed, the top surface 47 seamlessly aligns with the baffle 50, asit extends across the lower portion of the seed chamber 10. The centreof the upper door portion 44 provides a rectangular conduit 46 havingsubstantially the same cross-sectional area as the second flow passage35. As such, when the door 40 is closed, the first and second flowpassages 33, 35 are separated from one another and unobstructed, asillustrated in FIG. 4.

The upper door portion 44 swings free from inside the unit 1 and pivotsaway from the base 12 when the door 40 is rotated about hinge 42.Simultaneously, the conduit 46 and top surface 47 are disconnected fromthe baffle 50 thereby providing access to the second flow passage 35,and access to the first flow passage 33, through the baffle 50. Thisfacilitates access to the interior cavity 11 of the unit 1, asillustrated in FIG. 5.

The door 40 is also contemplated to be easily removable, and easilyreplaceable without the need to uncouple the unit 1 from the hopper 85.

The dual airflows 32, 34 as described herein assist in providing asteady and even flow of seed through the entrainment unit 1. The dualflow can be used to effectively entrain and thereby distribute differentgrain sizes, reducing the need to adjust air pressure and fan speed intothe unit 1 when switching from one seed to another.

In some embodiments, like that illustrated in FIGS. 10A-10B and 11A-11B,the door 40 can be provided with a plurality of stiffening webs 48.These webs48 provide stiffness and thus support for the door 40, withoutundue weight penalty.

Also illustrated in FIG. 10A, on a front face 8 of the wall form 5 is amounting boss 49 having a pair of apertures for receiving a latch 53.The boss 49 is integrally formed with the wall form 5.

The latch 53 is rigidly mounted to the wall form 5 via a pair of screws(or bolts, rivets, or studs). Hinged to, and extending from, a first endof the latch 53 is an engagor illustrated in FIG. 10B as a hook 54. Thehook 54 extends along the wall form 5 and captures a portion of the door40, to hold the door in a closed position. The latch 53 also comprises arelease 58, that is spring-loaded. When the release is actuated, thehook 54 is freed to extend away from the door 40, releasing the door 40and allowing the door 40 to swing open away from the base 12 of the wallform 5, emptying any trapped seed from the door 40 and neighbouringinternal areas of the entrainment unit 1. To re-seal the entrainmentunit 1, the door 40 is rotated back into the closed position, where thehook 54 is located onto the perimeter of the door 40. The latch 53 isthen clicked into place against the spring of the release 58, to retainthe latch 53 and the door 40 in the closed position.

Multi-Discharge Outlet Unit

The wall form 5 is modular by design, and can be abutted in side-by-siderelationship with a plurality of wall forms 5 to provide amulti-discharge outlet 25 unit 1, illustrated in FIG. 6.

The modular unit 1 can be configured to match the output needs of anexisting planter and retrofitted thereto.

Each of the wall forms 5 is configured as described above, and providesan outlet snorkel 35 and a door 40 for internal access to the cavity 11therein. Without a second end plate 15 interleaved between each of thewall forms 5, the seed chamber 10 of each of the wall forms 5 becomescombined into a single, increased capacity seed chamber 10. Furthermore,each of the air intake apertures 21 of each wall form also becomescombined within the single air supply 31 to drive the unit 1. However,each individual mixing chamber 20 of each individual wall form 5 remainseparate. Keeping the mixing chambers 20 separated facilitates thedesirable conditions for entraining seed within the combined air flow 36of each mixing chamber 20 and minimising the opportunity for damming ofany one of the snorkels 25.

Illustrated in FIG. 7 is an entrainment unit 1 according to oneembodiment of the invention, having 20 wall forms 5 abutted side-by-sidebetween the pair of end plates 15. Each individual wall form 5 is boltedto an open base of the hopper 80. An air source is introduced into theunit 1 from the air hose 85. A similar air hose 85 is mounted at theopposing end of the unit via a second of the pair of end plates 15(illustrated in FIG. 9).

A discrete seed discharge hose 86 is coupled to each of the snorkels 25for disbursing the entrained seed and air directly to a seed meteringunit 95 (illustrated in FIGS. 8 and 9). It is preferable that thedischarge hoses 86 are not kinked or turned through any tight angles todisrupt the flow or air and entrained see therein.

It is contemplated that a wall form 5 could be adapted in accordancewith the invention as described herein, such that the snorkel 25 isconfigured to discharge entrained seed and air in a predetermineddirection to suit specific planter 90 and hose 86 arrangements.

Although not visible in FIGS. 6-8 it is contemplated that a resilientseal be located and compressed between each pair of wall forms 5, andalso between the wall form 5 and the adjacent end plate 15. The sealwould provide for a better seal within the internal cavity 11 and reduceair gaps that could reduce efficiency of the unit 1. Seals are alsocontemplated for use between the air inlet manifold 84 and its attachedair hoses 85 and between the top end of the snorkel 24 and its attachedseed discharge hose 86.

In one embodiment, there is provided a method of distributing seed,comprising the steps of: supplying seed in bulk to a seed chamber 10;entraining seed in a first air 32 flow in the seed chamber 10;transporting the seed from the seed chamber 10 into a mixing chamber 20;supplying a second air flow 34 directly to the mixing chamber 20 so thatthe first and second air flows 32,34 mix seed entrained in the first airflow 32 in the mixing chamber 20 and transport the seed through adischarge outlet 25 of the mixing chamber 20.

It is contemplated that the air flow 32 and second air flow 34 can beprovided from two different air sources. Using the form work 5 describedherein, the air source is delivered into the air chamber 30 of theentrainment unit 1 and upon exiting the air chamber 30 via the chamberoutlet 37, the air is directed into the two separate air flows 32 and34.

The air chamber outlet 37 is divided into two passages 33, 35 toseparate the air flow into first 32 and second 34 flows. The outlet 37is divided by a baffle 50 that extends from the air chamber 30 into themixing chamber 20. The two air flows 32, 34 are drawn along opposingsides of the baffle with a laminar flow. The baffle 50 provides a commonwall between the two passage ways 33, 35 that keeps the two air flows32, 34 separate.

The first air flow 32 is directed towards the seed chamber 20 of theunit 1, to entrain seed therein and to transport the seed to the mixingchamber 20. The first air flow 32 travels across a top surface 47 of thebaffle 50 which passes through a lower portion of the seed chamber 10.

The seed becomes entrained within the first air flow 32 and is thentransported to the mixing chamber along the top surface 47 of the baffle50. As the seed entrained within the first air flow 32 is forces intocontact with the lip 52 of the baffle 50, the laminar air flow 32 isdisrupted and the vortices are created within the air flow 32 causingthe air flow 32 to become turbulent. The turbulent air flow 32 reducedthe opportunity for the seed therein to become blocked or stuck in theentrance 38 of the mixing chamber 20. The turbulent air flow 32 alsoforces the seed upwardly in the mixing chamber 20 towards the dischargeoutlet 25. The lip 39 of the lower portion of mixing chamber wall 29reduces the opportunity for entrained seed captured in the now turbulentfirst air flow 32 from being pushed back towards the seed chamber 10.

The second air flow 34 is not brought into contact with seed until itreaches the mixing chamber 20. The second air flow 32 is drawn along anunderside of the baffle 50, which forms the second passage 35 incombination with the base 12 of the wall form 5. The second air flow 34travels along the second passage 35 in a laminar flow. Ideally the first33 and second 35 passages are free form any intrusions or projectionsthat could restrict the air flows 32, 34 or reduce the efficiency of theentrainment unit 1.

As the second air flow 34 reaches the mixing chamber the laminar airflow 34 is directed upwards along the front face 8 of the wall form 5,partly guided by the front face 8 and partly guided by the lip 52 at theend of the baffle 50. As the second air flow 34 travels upwards in themixing chamber 20, it meets the first air flow 32 and entrained seed,combining to form a combined air flow 36 entraining the seed therein.

As the second air flow 34 travels towards the entrance to the mixingchamber 38, the second air flow 34 pulls the seed entrained in the firstair flow 32 into the mixing chamber 20 as the two air flows combine. Thepushing of the seed towards the mixing chamber 20 from the first airflow 32 is enhanced by the pulling of the seed into the mixing chamber20 of the second air flow 34, further reducing the opportunity for theseed to block the mouth of the mixing chamber 38.

The method as described herein supplies the first air flow 32 and thesecond air flow 34 as parallel air flows into the mixing chamber 20 sothat the second air flow 34 facilitates drawing the first air flow 32with entrained seed into the mixing chamber 20 and minimises thepossibility of blockages of the entrained seed from the seed chamber 10.

As the second air flow 34 joins the first air flow 32 and entrainedseed, the velocity of the fluid flow through the mixing chamber 20 isincreased, driving the seed entrained within the combined air flow 36upwardly and out of the snorkel 25 in a steady and even stream. From thesnorkel 25, the entrained seed is directed to a seed metering machine inpreparation for sowing.

It will be appreciated by persons skilled in the art that numerousvariations and modifications may be made to the above-describedembodiments, without departing from the scope of the following claims.The present embodiments are, therefore, to be considered in all respectsas illustrative of the scope of protection, and not restrictively.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, a limitednumber of the exemplary methods and materials are described herein.

It is to be understood that, if any prior art publication is referred toherein, such reference does not constitute an admission that thepublication forms a part of the common general knowledge in the art, inAustralia or any other country.

In the claims which follow and in the preceding description of theinvention, except where the context requires otherwise due to expresslanguage or necessary implication, the word “comprise” or variationssuch as “comprises” or “comprising” is used in an inclusive sense, i.e.to specify the presence of the stated features but not to preclude thepresence or addition of further features in various embodiments of theinvention.

LEGEND

No. 1 Entrainment unit 3 Open top 4 Mounting flanges 5 Wall form 6 Endplate mounting apertures 7 Unit mount holes 8 Front face of wall form 9Support webs 10 Seed chamber 11 Wall form internal cavity 12 Base of thewall form 13 Opening in the base 14 Brackets 15 End plate 16 End platemount holes 17 Door mount holes 18 Rear face of wall from 19 Side wall20 Mixing chamber 21 Air intake aperture 22 End plate mount flange 23Projections 24 Top end of snorkel 25 Discharge outlet (snorkel) 26Inclined wall of mixing chamber 27 #2 wall of seed chamber 28 Upper wall29 Lower wall 30 Air chamber 31 Air supply unit 32 First flow 33 Firstflow passage 34 Second flow 35 Second flow passage 36 Combined flow 37Air chamber outlet 38 Mixing chamber entrance 39 Mixing chamber lip 40Door 41 Cylindrical members 42 Door hinge 43 Handle. 44 Upper doorportion 45 lip 46 conduit 47 Top surface 48 Stiffening web 49 Mountingboss 50 Baffle 52 End lip 53 Latch 54 Engagor 55 Internal wall 56Abutting edge 57 Receiving recess 58 Release 80 Seed Hopper 84 Air inletmanifold 85 Air hoses 86 Seed discharge hoses 90 Planter 95 Seedmetering units

The invention claimed is:
 1. An entrainment unit for distributing seed,comprising; a seed chamber for seed in bulk; a mixing chamber for mixingseed and air, the mixing chamber having a discharge outlet fordischarging entrained seeds; and an air supply means having an airoutlet divided into a first passageway and a second passageway for: (a)supplying a turbulent first air flow into the mixing chamber via thefirst passageway so that the first air flow travels into and across tothe seed chamber so that seed is entrained therein and transported tothe mixing chamber, and (b) supplying a laminar second air flow into themixing chamber via the second passageway, the second passagewayextending around the seed chamber and directly into the mixing chamberto combine with the first air flow and form a combined air flow thatdistributes the seed and transports the seed through the dischargeoutlet; wherein, in use, the combined air flow effectively entrains anddistributes seeds of different sizes and weights from the entrainmentunit without the need to adjust the air supply when switching from oneseed to another.
 2. The entrainment unit of claim 1, wherein the airsupply unit comprises an air chamber for receiving air from an airsource, the air source being one of a motor driven fan and a compressedair source.
 3. The entrainment unit of claim 1, wherein the firstpassageway includes a first passage outlet for the first air flow toenter into the seed chamber and the second passageway includes a secondpassage outlet for the second airflow to enter into the mixing chamber.4. The entrainment unit of claim 3, wherein the first passage outlet isin direct fluid communication with the seed chamber and the secondpassage outlet is in direct fluid communication with the mixing chamber.5. The entrainment unit of claim 4, wherein the first and secondpassageways are parallel to each other.
 6. The entrainment unit of claim5, comprising a baffle that separates the first and second passageways.7. The entrainment unit of claim 6, wherein the baffle provides a commonwall that extends between the first and second passageways from the airchamber to the mixing chamber.
 8. The entrainment unit of claim 7,wherein the common wall comprises three portions, namely an inclinedportion situated at least partially in the air chamber; a seed chamberportion that extends between the air chamber and the mixing chamber; andan upwardly curved portion that extends into the mixing chamber.
 9. Theentrainment unit of claim 8, wherein the inclined portion of the commonwall provides a leading edge to separate air exiting the air chamberinto the first and the second air flows.
 10. The entrainment unit ofclaim 8, wherein the upwardly curved portion of the common wall isconfigured to induce turbulence into the first air flow such that thefirst air flow enters the mixing chamber as a turbulent air flow. 11.The entrainment unit of claim 8, wherein the seed chamber portion of thecommon wall defines a lower wall of the seed chamber.
 12. Theentrainment unit of claim 1, further including an internal wall thatseparates the mixing chamber and the seed chamber.
 13. The entrainmentunit of claim 12, wherein the internal wall includes a curved surfacefor guiding the combined air flow towards the discharge outlet.
 14. Theentrainment unit of claim 1, wherein the seed chamber includes at leastone inclined side walls for funnelling seed under a gravitational forcetowards the mixing chamber.
 15. An entrainment unit for distributingseed, comprising; a seed chamber for seed in bulk; a mixing chamber formixing seed and air, the mixing chamber having a discharge outlet fordischarging entrained seeds; and an air supply means for: (a) supplyinga turbulent first air flow to the seed chamber so that the first airflow travels into and across the seed chamber and seed is entrainedtherein and transported to the mixing chamber, and (b) supplying alaminar second air flow directly to the mixing chamber so that thesecond air flow can be combined with the first air flow to form acombined air flow that distributes the seed and transports the seedthrough the discharge outlet; wherein, in use, the combined air floweffectively entrains and distributes seeds of different sizes andweights from the entrainment unit without the need to adjust the airsupply when switching from one seed to another.
 16. The entrainment unitof claim 1, wherein the air outlet of the air supply unit is one of aplurality of alike air outlets that together form a manifold.
 17. Theentrainment unit of claim 16, wherein the seed chamber is a common seedchamber, with each air outlet of the manifold being in fluidcommunication therewith.
 18. The entrainment unit of claim 16, whereinthe mixing chamber is one of a plurality of separate mixing chambers,with each air outlet of the manifold being in fluid communication withone of the mixing chambers.
 19. The entrainment unit of claim 18,wherein the discharge outlet is one of a plurality of separate dischargeoutlets, with each mixing chamber of the manifold being in fluidcommunication with one of the discharge outlets.
 20. The entrainmentunit of claim 15, wherein the air outlet of the air supply unit is oneof a plurality of alike air outlets that together form a manifold. 21.The entrainment unit of claim 20, wherein the seed chamber is a commonseed chamber, with each air outlet of the manifold being in fluidcommunication therewith.
 22. The entrainment unit of claim 20, whereinthe mixing chamber is one of a plurality of separate mixing chambers,with each air outlet of the manifold being in fluid communication withone of the mixing chambers.
 23. The entrainment unit of claim 22,wherein the discharge outlet is one of a plurality of separate dischargeoutlets, with each mixing chamber of the manifold being in fluidcommunication with one of the discharge outlets.